SLI & Nvidia Surround - monitor for each card?

Discussion in 'nVidia Flavor' started by Psychor, Mar 1, 2015.

  1. Psychor

    Psychor Limp Gawd

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    A few months ago I read/watch a PCPER article/video which touched on Nividia Tri-SLI and using three displays - it might have been 3 Asus ROG Swifts. At the time Nvidia would not allow SLI to be enabled if you needed to use the DP on each of your 3 video cards. You'd have to only use the ports available on the primary video card which would be an issue if you needed 3 DPs but only had one on the primary video card.

    Evidently Nvidia was made aware of this issue and evidently stated that it would be fixed. Can anyone confirm whether or not it was fixed? In other words, I'm hoping that you can now enable SLI for 3 Nvidia video cards while using 3 displays where each display is connected, via DP, to a different video card.

    Thanks.
     
    Last edited: Mar 1, 2015
  2. CrazyRob

    CrazyRob [H]ard|Gawd

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    The issue you're referencing is in regard to gsync in particular. For non gsync displays, in 3 way sli, you are required to connect each display to a separate video card, whether you're using display port, hdmi, or dvi. Gsync had not yet been supported, but I have not heard if that has changed yet.
     
  3. martinje

    martinje [H]ard|Gawd

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    When I used to run Nvidia Surround Portrait I used the DVI ports of my Nvidia Card. I used 2 from the primary and 1 from the secondary. I do remember AMD video cards required all monitors hook up to the same video card.

    That was a year and a half ago. Dont know if that's still accurate.
     
  4. Psychor

    Psychor Limp Gawd

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    Ah, that was it - that GSYNC was the issue. Thanks.

    This is what I'm hoping gets fixed:
    https://rog.asus.com/forum/showthread.php?49976-GSync-Multiple-PGs-in-Surround-Tri-SLI
    http://rog.asus.com/forum/showthread.php?50016-Confusion-over-Swift-PG278Q-display-port-1-2
    https://forums.geforce.com/default/...nd-g-sync-will-it-work-/post/4091076/#4091076
     
    Last edited: Mar 1, 2015
  5. crimsonyoshi

    crimsonyoshi Limp Gawd

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    I'm fairly sure it was this forum I posted in a few months back regarding your question - do a search for some of my prior posts. If nothing shows up for this, then sorry, it may have been another forum.

    Short version, yes 3 way sli with g-sync will work with ROG PG278Q's. The catch is you need 980's to do it.

    980's have 3 DP's (at least) - so I queried Asus and NVidia about your exact question back in November or December, they both said the same thing. The answer was if you're going to 2 or 3 way SLI and want g-sync running on all monitors, you need to plug all 3 monitors into the first card, and have the other 1 or 2 cards SLI'ed together, with nothing plugged into them. It was either the first or second release of drivers after the 980's came out that enabled this feature, but it is 100% possible. I'm planning to build a rig with this exact setup, but I'm holding out to see what's after the 980's in terms of power. The games I play will work fine for 980's as above, but I like to make sure I'm just a bit ahead of 'fine.'
     
  6. Psychor

    Psychor Limp Gawd

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    Gotcha. But I'm concerned about those with GTX 980s that only has 1 DP per card (e.g., EVGA GTX 980 Classified, etc.). If you tri-SLI those type of cards you're screwed and that's ridiculous. From what I understand this was suppose to be addressed by Nvidia where you could use the DP port for each card.
     
  7. Eymar

    Eymar Limp Gawd

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    I have been running 3x Swift in surround+G-Sync with 980s tri-sli with one connection per card since 980 release time.
    [​IMG]
     
    Last edited: Mar 3, 2015
  8. Psychor

    Psychor Limp Gawd

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    Interesting - thanks for posting this.

    I wonder what the difference is between the first option and the second in terms of how the GPUs work together.
     
  9. Eymar

    Eymar Limp Gawd

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    I will try to see if there is a difference if all monitors connected to single card. I've been using a surround setup since 580's so always connected one monitor to one video card as that was original surround requirement. I assumed all is good with 980 setup since most games look smooth (exception being FC3) and G-Sync led indicator is on for each Swift.